Catheter-based tissue remodeling devices and methods

ABSTRACT

Devices and methods utilizing a catheter to remodel soft tissue of a patient and, in a preferred embodiment, to reduce the volume of the left ventricle of a heart. In some embodiments, one or more sutures are passed through a wall of the ventricle. The ends of the one suture and, more preferably, the multiples sutures are drawn together to draw tissue portions towards one another. In some embodiments, a tissue remodeling clip is implanted into a wall of the ventricle. Ends of the clip are resiliently biased to move relative to one another to draw tissue portions towards one another. In some embodiments, a tissue remodeling anchor includes a base and a plurality of legs attached to the base. The legs of the tissue anchor are implanted into a wall of the ventricle and moved toward one another to draw tissue portions toward one another.

RELATED APPLICATIONS

This application is a continuation of, and claims priority from, U.S.patent application Ser. No. 11/060,268, filed on Feb. 17, 2005, whichclaims the benefit of U.S. Provisional Patent Application No.60/627,821, filed Nov. 15, 2004, the entireties of both of which arehereby incorporated by reference herein and made a part of the presentdisclosure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to methods for remodeling soft tissue of apatient and, preferably, for remodeling the left ventricle of apatient's heart. The present invention also relates to systems foraccomplishing the preferred methods.

2. Description of the Related Art

Congestive heart failure is a description given to a myriad of symptomsthat may be the result of the heart's inability to meet the body'sdemand for blood flow. Heart failure may be considered as the conditionin which an abnormality of cardiac function is responsible for theinability of the heart to pump blood at a rate commensurate with therequirements of the metabolizing tissues, or can do so only at anabnormally elevated filling pressure. There are many specific diseaseprocesses that can lead to heart failure. Typically, these processesresult in dilation of the left ventricular chamber.

The process of ventricular dilation may be the result of chronic volumeoverload or may result from a specific damage to the myocardium. In anormal heart that is exposed to long-term increased cardiac outputrequirements, for example, that of an athlete, there is an adaptiveprocess of slight ventricular dilation and muscle hypertrophy. In thisway, the heart compensates for the increased cardiac outputrequirements. With damage to the myocardium, or chronic overload,however, there are increased requirements put on the contractingmyocardium to such a level that this compensated state is never achievedand the heart continues to dilate.

One condition that is likely to reduce the blood pumping efficiency ofthe heart muscle is ventricular dilation. As the chamber becomesenlarged, the internal surface area of the chamber increases rapidly.Blood flowing within the heart applies pressure to the internal surfaceof the heart chamber and because the blood applies pressure inside theheart chamber across an increased surface area, the force which must beproduced by the heart in order to pump blood also increases. In manycases, the cardiac disease responsible for the ventricular dilation alsolimits the ability of the heart muscle to produce the increased forcerequired to efficiently pump blood, which further compounds the problem.

In many cases, the dilation of the heart chamber becomes progressivelyworse and the blood pumping efficiency of the heart muscle progressivelydeclines. As this situation worsens, the location area of compromisedmyocardium may bulge out as the heart contracts, further decreasing theheart's ability to move blood forward. When local wall motion moves inthis way it is said to be dyskinetic. The dyskinetic portion of themyocardium may stretch and eventually form an aneurismic bulge.

There is no cure for heart failure, but it can be treated. The primarygoals of treatment are to relieve symptoms and prevent worsening of thecondition. Symptoms may be relieved by removing excess fluid from thebody, improving blood flow and increasing delivery of oxygen to the bodytissues. Medical treatment usually comprises lifestyle changes andmedications. For example, diuretics have been used to reduce extracellular fluid which accumulates in congestive heart failure patients,thereby increasing the preloaded condition of the heart. Nitrates,arteriolar vasodilators and angiotensin converting enzyme (ACE)inhibitors have been used to treat heart failure through the reductionof cardiac workload by reducing afterload. Inotropes function toincrease cardiac output by increasing the force and speed of cardiacmuscle contraction. These drug therapies offer some beneficial effects,but do not stop the progression of the disease.

With respect to the situation of a dilated left ventricle or aneurismbulge, a variety of surgical studies have demonstrated some clinicalsuccess of ventricular remodeling and treatment of the dilation of theinfarcted ventricle. One such remodeling procedure is referred to as theBatista Procedure. In the Batista Procedure, a small portion of theenlarged lower left ventricle chamber of the heart is removed to reducethe size of the left ventricle towards normal. Typically, the Batistaprocedure involves the surgeon locating the left anterior descendingcoronary artery and making two small cuts down and outward to remove awedge of the left ventricle. The remaining edges of the left ventricleare sewn together, returning the chamber to near its normal size. Theincision is closed and the surgery is completed.

A variation of the Batista Procedure, referred to as the Dor Procedure,involves a lengthwise incision in the left ventricle along an areadamaged by a myocardial infarction. The undamaged areas of the ventricleare sutured back together, eliminating the affected area. If the damagedarea is too large, a patch may be used to cover the damaged area.However, in each of the Batista and Dor procedures, restoration ofnormal ventricular shape is a complex surgical procedure and veryinvasive for the patient. Furthermore, these procedures are notapplicable to those patients that are not candidates for such invasivesurgery.

SUMMARY OF THE INVENTION

Preferred methods of the present invention permit remodeling, tissuejoining or tying of the left ventricle using a catheter-basedpercutaneous approach, which is far less traumatic to the patient thanthe Batista and Dor procedures. In addition, the methods and preferreddevices disclosed herein may be adapted for use in remodeling softtissue of a patient other than the left ventricle.

A preferred method of remodeling a ventricle of a heart includesintroducing a distal portion of at least one catheter through the aortainto the ventricle. The method also includes utilizing the at least onecatheter to urge tissue portions on a same side of the ventricle towardseach other and to secure the tissue portions such that the volume of theventricle is reduced.

Another preferred method of decreasing the volume of a ventricle of aheart includes providing an implant in contact with a wall of theventricle at a contact location internal to the exterior surface of theheart and urging adjacent tissue portions located on a same side of theventricle towards each other by applying force to the wall with theimplant at the internal contact location.

Still another preferred method of reducing the volume of a ventricle ofa heart includes gathering tissue by folding a pair of adjacent tissueportions of a wall of the ventricle and repeating the folding to providea plurality of tissue folds. The gathering comprises securing theplurality of tissue folds to retain the folded portions in closeproximity by advancing at least one implant through the interior of theventricle and securing the implant to a wall of the ventricle.

A preferred embodiment is a cardiac treatment apparatus including acatheter having a catheter body configured to be introduced into a heartchamber through vasculature. The catheter includes a suture passage anda suture passing through the passage. The suture has an end portion. Atissue penetration member is movably mounted within the catheter bodysuch that the penetration member enters an interior surface of a wall ofthe heart at a first location and exits the interior surface at a secondlocation spaced from the first location. The penetration member isadapted to deliver the suture through the tissue between the locations,whereby application of tension to end portions of the suture draws thetissue locations towards each other.

Another preferred embodiment is a cardiac treatment apparatus includinga catheter having a catheter body configured to be introduced into aheart chamber through vasculature. The catheter includes a clip havingend portions. The clip is movably mounted in the catheter body such thatone end portion enters an interior surface of a wall of the heart tointroduce at least a substantial portion of the clip into the wall. Anintermediate portion of the clip is embedded in the wall and the endportions are resiliently biased to move relative to each other such thatthe movement of the end portions draws tissue portions towards eachother.

Yet another preferred embodiment is a cardiac treatment apparatusincluding a catheter having a catheter body configured to be introducedinto a heart chamber through vasculature. The catheter includes a tissueanchor having a plurality of legs attached to a base. The legs areconfigured to pass through an interior surface of a wall of the heartand anchor the legs of the tissue anchor to the wall. The anchored legshave a first position upon the anchoring and are subsequently movable toa second position. The movement of the legs to the second position drawsportions of tissue towards each other. The catheter also includes aretaining member for retaining the anchored legs in the second positionwhen the catheter body is removed from the heart.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the present tissueremodeling devices and methods are described in greater detail belowwith reference to drawings of several preferred embodiments, which areintended to illustrate but not to limit the present invention. Thedrawings contain 40 figures.

FIG. 1 is a perspective view of a system for remodeling a left ventricleof a heart. The illustrated system includes certain features, aspectsand advantages of a first embodiment. The remodeling system includes acatheter having a pair of coaxial catheter bodies.

FIG. 2 is an enlarged view of a distal end of the catheter of FIG. 1.The distal end of the catheter carries an inflatable balloon.

FIG. 3 is a cross-sectional view of the distal end of the catheter ofFIG. 1, with the balloon illustrated in an inflated condition.

FIG. 4 is a partial cross-sectional view of the catheter of FIG. 1illustrating a tissue remodeling clip that is positioned within a distalend of the inner catheter body.

FIG. 5 a is a side view of the catheter in a position wherein a distalend of the inner, tissue-penetrating catheter body is extended from theouter, guide catheter body. FIG. 5 b is an end view of thetissue-penetrating catheter of FIG. 5 a as viewed in the direction ofthe arrow 5 b of FIG. 5 a.

FIGS. 6 a-c are several views of a first embodiment of the tissueremodeling clip illustrating several positions of the clip. FIG. 6 a isa view of the clip in a relaxed position. FIG. 6 b is a view of the clipin a biased position and, in particular, a substantially straightenedposition that may occur when the clip is docked within the catheter.FIG. 6 c is a view of the clip implanted within soft tissue in a tissueremodeling position.

FIGS. 7 a-d are several views of a modification of the clip of FIG. 6,wherein the ends of the clip include pledgets. FIG. 7 a is a view of theclip in a relaxed position. FIG. 7 b is a view of the clip in astraightened position with its end pledgets in an expanded orientation.FIG. 7 c is a view of the clip in a straightened position and its endpledgets in a collapsed position. FIG. 7 d is a view of the clipimplanted within soft tissue in a tissue remodeling position.

FIGS. 8 a-c are several views of yet another modification of the clip ofFIG. 6 in several positions. FIG. 8 a is a view of the clip in a relaxedposition. FIG. 8 b is a view of the clip in a straightened position.FIG. 8 c is a view of the clip implanted in soft tissue in a tissueremodeling position.

FIG. 9 is a schematic illustration of the system being used to remodel aleft ventricle of a patient's heart and being introduced into thepatient's vasculature through the femoral artery.

FIG. 10 is a cross-sectional view of the patient's heart with thecatheter within the left ventricle and the balloon in an inflatedposition.

FIG. 11 consists of several views illustrating several steps of apreferred method of using the catheter-based system of FIG. 1. FIG. 11 ais a cross-sectional view of the patient's heart with the catheter incontact with a wall of the left ventricle and the tissue-penetratingcatheter penetrating the wall of the left ventricle. FIG. 11 b is anenlarged view of a distal end portion of catheter with thetissue-penetrating catheter being rotated about is longitudinal axis tocreate a generally helical passage within the wall of the leftventricle. FIG. 11 c is an enlarged view of the heart with the clipimplanted into the passage created by the tissue-penetrating catheter.FIG. 11 d is an enlarged view of the heart with the clip in a tissueremodeling position. FIG. 11 e is a view of the clip of FIGS. 7 a-dimplanted into the wall of the ventricle and in a tissue remodelingposition.

FIG. 12 is a cross-sectional view of the heart illustrating severaltissue remodeling clips positioned within the left ventricle.

FIG. 13 is perspective view of a modification of the tissue remodelingsystem of FIG. 1 and includes a catheter configured to deploy acollapsible tissue anchor.

FIG. 14 is a perspective view of a tissue anchor delivery catheter bodyof the system of FIG. 13.

FIG. 15 is a partial cross-sectional view of the tissue anchor deliverycatheter of FIG. 14.

FIG. 16 a is a perspective view of the collapsible tissue anchor in acollapsed position. FIG. 16 b is a perspective view of the tissue anchorin a relaxed position.

FIG. 17 includes several views of the tissue anchor being deployed fromthe anchor delivery catheter. FIG. 17 a is an enlarged, partialcross-sectional view of the tissue anchor docked within a distal end ofthe delivery catheter. FIG. 17 b is a view of the tissue anchor deployedfrom the delivery catheter and assuming a relaxed position. FIG. 17 c isa view of a retaining member delivered onto the tissue anchor to retainthe tissue anchor in a tissue remodeling position.

FIG. 18 is a cross-sectional view of a heart with the catheter insertedinto the left ventricle.

FIG. 19 is a cross-sectional view of the heart of FIG. 18 illustratingthe tissue anchor deployed from a distal end of the delivery catheter.

FIG. 20 is a cross-sectional view of the heart of FIG. 18 illustratingthe tissue anchor penetrating the wall of the left ventricle.

FIG. 21 is a cross-sectional view of the heart of FIG. 18 illustratingthe retaining member retaining the tissue anchor in a tissue remodelingposition.

FIG. 22 is a cross-sectional view of the heart of FIG. 18 illustratingthe tissue anchor released from the catheter and remodeling the wall ofthe left ventricle.

FIG. 23 is a cross-sectional view of yet another modification of thetissue remodeling system of FIG. 1. The system of FIG. 23 includes acatheter configured to deliver a suture into the wall of the leftventricle and including an access catheter body and a suture deliverycatheter body.

FIG. 24 is an enlarged view of a distal end of the catheter of FIG. 23.

FIG. 25 is a cross-sectional view of the catheter of FIG. 23 taken alongthe view line 25-25 of FIG. 23.

FIG. 26 is a perspective view of the guide catheter of FIG. 23 havingthe suture delivery catheter replaced by a clip delivery catheter thatis configured to deliver a retaining clip.

FIG. 27 is a cross-sectional view of a distal end portion of the clipdelivery catheter of FIG. 26.

FIG. 28 a is a perspective view of the clip removed from the deliverycatheter and illustrated in a biased open position. FIG. 28 b is aperspective view of the clip of FIG. 28 a in a relaxed position.

FIG. 29 is a perspective view of the access catheter of FIG. 23 and aknot pusher which may be used to push a knot in the suture from anexposed end of the suture through the catheter to a position behind theretaining clip.

FIG. 30 is a perspective view of the access catheter of FIG. 23 with thesuture delivery catheter replaced by a suture cutting catheter.

FIGS. 31 a-c are several views of a distal end portion of the suturecutting catheter of FIG. 30 indicated by the view line 31 of FIG. 30.FIG. 31 a is a cross-sectional view of a distal end portion of thesuture cutting catheter. FIG. 31 b is an end view of the suture cuttingcatheter. FIG. 31 c is a cross-sectional view of the suture cuttingcatheter taken along view line 31 c-31 c of FIG. 31 a.

FIG. 32 is a schematic illustration of the tissue remodeling system ofFIGS. 23-31 being introduced into a patient to remodel the leftventricle of the patient's heart by accessing the patient's vasculaturethrough the femoral artery.

FIG. 33 a is a cross-sectional view of the patient's heart illustratingthe system delivering a suture through a wall of the left ventricle.FIG. 33 b is an enlarged view of the distal end of the suture deliveringcatheter.

FIG. 34 a is a cross-sectional view of the patient's heart illustratingthe suture delivered through the wall of the left ventricle and thecatheter released from the wall of the heart. FIG. 34 b is an enlargedview of the catheter of FIG. 34 a.

FIG. 35 is a cross-sectional view of the patient's heart illustratingthe suture delivery catheter delivering another suture to the ventriclewall.

FIG. 36 is a cross-sectional view of the patient's heart illustratingthe suture delivery catheter delivering yet another suture to theventricle wall.

FIG. 37 is a cross-sectional view of the patient's heart illustratingmultiple sutures implanted in the ventricle wall with both free ends ofthe sutures extending through the access catheter.

FIG. 38 is a cross-sectional view of the patient's heart illustratingthe clip delivery catheter of FIG. 26 delivering a retaining clip ontothe sutures.

FIG. 39 is a cross-sectional view of the patient's heart illustratingthe retaining clip gathering the sutures to draw tissues portion of theventricle toward one another and reducing the volume of the ventricle.

FIG. 40 is a cross-sectional view of the patient's heart illustratingthe gathered sutures and retaining clip secured by knots in the suturesbehind the retaining clip. The ends of the sutures are cut behind theknots, preferably by a device such as the suture cutting catheter ofFIG. 30.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiments and methods of the present tissue remodelingsystem permit remodeling, tissue joining, or tying of soft tissue and,in certain preferred arrangements, permit a remodeling of the leftventricle of a heart to reduce the volume of the ventricle. Preferably,the preferred embodiments permit soft tissue remodeling while avoidingthe disadvantages of more invasive procedures and the complications thatmay occur as a result of such procedures. The preferred embodiments andmethods may also permit tissue remodeling in patients that are otherwiseunable to undergo conventional surgical procedures, such as open heartsurgery. Preferred embodiments of the present system permit theduplication of the results of surgical procedures in reducing the volumeof the left ventricle by a percutaneous transvascular technique usingcatheter-based devices. In addition, the preferred embodiments andmethod disclosed herein may be modified or adapted for use in theremodeling of soft tissue other than the left ventricle of a patient'sheart.

FIGS. 1-8 illustrate a first preferred embodiment of a tissue remodelingsystem, generally referred to by the reference numeral 50. Theillustrated system 50 includes a catheter assembly 52, which preferablyincludes multiple catheters, or catheter bodies. For simplicity, boththe catheter assembly 52 and individual catheter bodies may be referredto by the term “catheter.” Preferably, the catheter 52 is sized, shapedand otherwise configured to be movable within a patient's vasculature toa desired remodeling site from a desired insertion site, such as thefemoral artery, for example.

Thus, the catheter 52 may be constructed from a variety of suitablematerials using a variety of suitable fabrication techniques, such asthose commonly known and used in constructing catheters for medical use.For example, the catheter 52, and other catheters discussed herein, maybe constructed from polyethylene, polyurethane, silicone orpolytetraflouroethylene, or other suitable materials by any suitableprocess. The illustrated catheter 52 includes a pair of coaxial catheterbodies. The outer catheter body 54 is referred to as a guide catheter,or access catheter, herein. The illustrated access catheter 54 may havean outer diameter of about 26 F (French) and an inner (lumen) diameterof about 22 F. However, other suitable dimensions may be selected tosuit an individual application of the catheter 54.

The inner catheter 56 is movable within the access catheter 54 and isreferred to as a tissue-penetrating catheter herein. The inner catheter56, in the illustrated arrangement, preferably has an outer diameter ofabout 18 F and an inner (lumen) diameter of about 13 F. However, otherdimensions may be selected to suit a desired application of the catheter56.

In the illustrated arrangement, the access catheter 54 is configured tobe steerable to permit the access catheter 54 to be guided throughvasculature to a desired site. Preferably, an anchoring ring 58 isembedded within a distal end 54 a of the access catheter 54. Adeflection wire 60 preferably is connected to and extends from theanchor ring 58 within a wall of the catheter 54 to a proximal end of thecatheter 54 where it is connected to a control knob 62. Thus, thecontrol knob 62 permits a user to selectively move the deflection wire60 relative to the catheter 54 to deflect a distal end 54 a of theaccess catheter 54. Deflection of the distal end 54 a of the accesscatheter 54 assists a user to routing the catheter 54 through thevasculature of a patient in a desired path. Alternatively, othersuitable steering arrangements or positioning methods of the accesscatheter 54 may be employed. In one arrangement, the access catheter 54may be configured to slide over a previously placed guidewire (notshown).

Preferably, the distal end 54 a of the access catheter 54 is configuredto be atraumatic to the patient and, in particular, to the tissue at ornear the remodeling site. In the illustrated arrangement, the distal tip54 a of the access catheter 54 carries an inflatable, annular balloon64. Preferably, the balloon 64 is normally carried by the accesscatheter 54 in an uninflated condition so as not to interfere with thepassage of the catheter 54 through a patient's vasculature. Once inplace within the left ventricle, the balloon 64 may be inflated tocontact the ventricle wall, help stabilize the distal end of the accesscatheter 54 and inhibit a distal tip 54 a of the access catheter 54 fromdamaging tissue. Preferably, the balloon 64, in an inflated condition,extends beyond an end surface of the distal end 54 a to inhibit thedistal end surface from contacting the wall of the heart. The balloon 64may be constructed from a suitable, material and mounted to the accesscatheter 54 by any suitable technique.

An inflation passage 66 is defined within a wall of the access catheter54 and communicates with an interior space of the balloon 64. A proximalend of the inflation passage 66 extends from a proximal end 54 b of theaccess catheter 54, preferably on a handle defined by the proximal end54 b and near the steering knob 62. Thus, the inflation passage 66 maybe connected to a suitable fluid supply source 68, which is configuredto supply a pressurized fluid to the balloon 64 through the inflationpassage 66. In the illustrated arrangement, the source of fluid 68 is astandard syringe that is connected to the inflation passage 66preferably by suitable plastic tubing 70. Any type of suitableconnector, such as a luer lock for example, may be used to interconnectthe tubing 70 with the access catheter 54 and the source of fluid 68. Ifdesired, a pressure indicator 72 may be provided within the system toprovide an indication of the fluid pressure within the balloon.

As described above, the tissue-penetrating catheter 56 is movable withinthe access catheter 54. Preferably, the tissue-penetrating catheter 56is movable to a stowed position within the access catheter 54 wherein,preferably, the entire distal end 56 a of the tissue-penetratingcatheter 56 is positioned within the distal end 54 a of the accesscatheter 54. Preferably, the tissue-penetrating catheter 56 is alsomovable to a protruding position relative to the access catheter 54wherein the distal end 56 a of the tissue-penetrating catheter 56 isexposed from the distal end 54 a of the access catheter 54. Preferably,a proximal end 56 b of the tissue-penetrating catheter 56 defines ahandle configured to permit a user to move the tissue-penetratingcatheter 56 between its stowed and protruding positions.

In the illustrated arrangement, the distal end 56 a of thetissue-penetrating catheter 56 is configured to create a passage withinsoft tissue of a patient and deliver an implant, or a tissue remodelingclip 74, into the passage. With reference to FIGS. 1 and 4, preferablythe tissue-penetrating catheter 56 carries the tissue remodeling clip 74within its distal end 56 a. In the illustrated arrangement, a push rod76 is positioned within the tissue-penetrating catheter 56 and proximalof the clip 74. The distal end 76 b of the push rod 76 preferablydefines a contact surface configured to permit the push rod 76 to applya force to the clip 74. A proximal end 76 b of the push rod 76terminates in a handle, which permits a user of the system 50 to deploythe clip 74 from the tissue-penetrating catheter 56 by advancing thepush rod 76 within the tissue-penetrating catheter 56.

Desirably, the distal end 56 a of the tissue-penetrating catheter 56assumes a nonlinear shape in a relaxed position. That is, preferably,when no restraining force is present on the distal end 56 a of thetissue-penetrating catheter 56, the distal end 56 a moves into anonlinear orientation. Preferably, in a relaxed position, the distal end56 a is arcuate or curved and, more preferably, assumes a generallyhelical shape. The helix angle, radius and length of the distal end 56 amay be altered to suit the properties of the tissue that to beremodeled. Preferably, at least the distal end 56 a of thetissue-penetrating catheter 56 preferably is constructed from a suitableshape memory material that is configured to have a desired shape in itsrelaxed position, such as a nickel titanium alloy (NiTi), for example.

With such an arrangement, when the tissue-penetrating catheter 56 is inits stowed position, the access catheter 54 constrains the distal end 56a into a generally straightened orientation, or a shape that generallymatches the shape of the distal end 54 a of the access catheter 54 at agiven time. However, when the tissue-penetrating catheter 56 is moved toits protruding position, the distal end 56 a tends to move toward itspredefined relaxed shape. In use, outside forces may inhibit the distalend 56 a of the tissue-penetrating catheter 56 from reaching its fullrelaxed orientation, such as forces imposed by the tissue in which thedistal end 56 a is penetrating. Preferably, the relaxed shape of thedistal end 56 a of the tissue-penetrating catheter 56 is configured suchthat the shape assumed by the distal end 56 a will be generally asdesired in the presence of anticipated restraining forces, such as thoseoriginating from soft tissue of a patient, for example. Furthermore,although a helical shape is preferred, in other applications othershapes may be desirable, as will be appreciated by one of skill in theart. Preferably, the tip of the distal end 56 a of thetissue-penetrating catheter is angled relative to a longitudinal axis ofthe catheter 56 to permit the distal end 56 a of the tissue-penetratingcatheter 56 to pierce soft tissue. Other suitable tip shapes that wouldpermit the catheter 56 to pierce or penetrate soft tissue may also beused.

Preferably, the tissue remodeling clip 74 is configured to be movablebetween a nonlinear, relaxed position and a biased, or straightenedposition. Thus, the clip 74 preferably is constructed from a shapememory material, such as NiTi. When stowed within the tissue-penetratingcatheter 56, preferably the clip 74 is biased into a generally linearorientation or a shape that generally matches the shape of the distalend 56 a of the tissue-penetrating catheter 56. When deployed from thetissue-penetrating catheter 56, the clip 74 moves toward its relaxedposition wherein, preferably, a first end 74 a of the clip 74 isresiliently biased to move toward a second end 74 b, as illustrated inFIG. 6 a. In the illustrated arrangement, the clip 74 in a relaxedposition assumes a generally circular shape. However, the clip 74 may beconfigured to assume other suitable shapes in its relaxed position.

The illustrated clip 74 may have a diameter from between about 0.005inches to about 0.05 inches. The circular loop defined by the clip 74 inits relaxed position may have a diameter from about 0.06 inches to about0.5 inches. A length of the clip 74 may be from about 0.5 inches toabout 2 inches. These dimensions are presently preferred for a clip 74configured to remodel the left ventricle of a patient's heart. In otherapplications, other dimensions may be desirable. The clip 74 may beshaped by winding a work piece on a mandrel and then exposing the workpiece to a heat cycle of about 500 degrees centigrade for a period ofbetween about 10 minutes to about 60 minutes, depending on the strength,spring rate and oxide layer desired. Furthermore, other suitable methodsof shaping the clip 74 may also be used.

As illustrated in FIG. 6 c, when implanted into soft tissue T, the clip74 moves toward its relaxed position such that the first end 74 aapplies a force to the tissue T at a first location and the second end74 b applies a force to the tissue T at a second location spaced fromthe first location to remodel the soft tissue T. As discussed above withrespect to the distal end 56 a of the tissue-penetrating catheter 56, inuse the clip 74 may not move completely to its relaxed position due torestraining forces, such as forces imposed by the soft tissue. Thus, thetissue remodeling position of the clip 74 may fall somewhere between itsstraightened position and its relaxed position. Furthermore, the ends 74a, 74 b of the clip 74 may remain embedded within the soft tissue T.However, preferably the clip 74 does not protrude through an externalsurface of the tissue wall (the non-entry side of the wall). That is,when the clip 74 is implanted within a ventricle of a heart, preferably,the clip 74 enters the heart wall from a location internal the ventricleand does not pass through an outer surface of the heart wall.

FIGS. 7 a-7 d illustrate a modification of the tissue remodeling clip 74and is generally referred to by the reference numeral 80. The clip 80includes a pledget at each of its first and second ends 80 a, 80 b. Thepledgets 82 preferably are relatively thin, circular members which havea diameter substantially larger than a diameter of the clip 80 when thepledgets 82 are in an expanded position (FIGS. 7 a, 7 b and 7 d).Therefore, the pledgets 82 inhibit the ends 80 a, 80 b of the clip 80,once passed completely through soft tissue T, from pulling back throughthe surface of the tissue T. Thus, the ends 80 a, 80 b of the clip 80preferably remain exposed from the tissue T. Preferably, the pledgets 82are collapsible to permit the clip 80 to be initially implanted into thetissue T, as illustrated in FIG. 7 c.

In a preferred embodiment, the pledgets 82 may be constructed from apiece of polymer material, such as Dacron, that is cut into a circularshape with a central aperture. The pledgets 82 may be placed over theends 80 a, 80 b of the clip 80 and the ends 80 a, 80 b enlarged toretain the pledgets 82 on the clip 80. The enlarged ends may be formedby resistance spot welding, laser welding, or other suitable methods.Further, the enlarged ends may be created by additional members that areseparate from, and secured to, the clip 80.

Another modification of the clip 74 of FIG. 6 is illustrated in FIGS. 8a-8 c and is referred to by the reference numeral 90. The clip 90 ofFIGS. 8 a-8 c includes a plurality of barbs 92 on each of the first andsecond ends 90 a, 90 b. The barbs 92 are configured to penetrate tissueto inhibit movement of the clip 90 relative to the tissue. The barbs 92(and ends 90 a, 90 b) may be embedded in the tissue T when the clip 90is implanted, as shown in FIG. 8 c, or, alternatively, may be exposedfrom the tissue T. The barbs 92 may be created by a laser cuttingtechnique, electrical discharge machining (EDM), mechanical cuttingtechniques, or other suitable processes. In addition, other suitablestabilizing members or arrangements to inhibit movement of the clips 74,80, 90 relative to the tissue into which they are implanted may also beused. Furthermore, although the illustrated clips 74, 80, 90 arecircular in cross-sectional shape, other suitable shapes may also beused, such as a rectangular or elliptical cross-section, for example.

FIGS. 9-12 illustrate a preferred method for utilizing the system 50 ofFIGS. 1-8 to remodel soft tissue of a patient P and, preferably, toremodel the left ventricle of the patient's P heart H. In a preferredapplication of the method illustrated in FIGS. 9-12, access to the leftventricle of the heart H is achieved through the patient's vasculature Vfrom an insertion site in the femoral artery F. If desired, a sleeve(not shown) may be inserted into the femoral artery F to provide accessfor the catheter 52. Alternatively, other methods of accessing the leftventricle, preferably using a percutaneous approach, may also be used.

With reference to FIG. 10, the catheter 52 is illustrated accessing theleft ventricle LV of the patient's heart through the aorta A. Thecatheter 52 may be routed to the left ventricle LV by any suitablemethod. For example, as described above, the catheter 52 may besteerable to permit a user to navigate the patient's P vasculature usinga suitable imaging technique. For example, preferably, the method isperformed by a cardiologist in a cathlab setting using a transesophagealechocardiogram (TEE) or angiographic fluoroscopy imaging technique toaccomplish each of the steps described herein that take place within thepatient P. In addition, other imaging techniques may also be used. Ifdesired, a guide wire (not shown) may be routed to the left ventricle LVand the catheter 52 may be introduced to the left ventricle LV over theguide wire.

As will be appreciated by one of skill in the art, a human heart Hincludes a right atrium RA, a left atrium LA, a right ventricle RV and aleft ventricle LV. The tricuspid valve TV separates the right atriumfrom the right ventricle and the pulmonary valve PV separates the rightventricle from the pulmonary artery PA. The mitral valve MV separatesthe left atrium LA from the left ventricle LV and they aortic valve AVseparates the left ventricle LV from the aorta A.

As illustrated in FIG. 10, in the preferred method, the balloon 64 isinflated so that the catheter assembly 52, and access catheter 54 inparticular, may be held against the wall of the left ventricle LVwithout causing damage thereto. Thus, preferably the balloon 64 supportsa distal tip of the access catheter 54 at least slightly spaced from thewall of the left ventricle LV. The balloon 64 may also contact the wallof the left ventricle LV adjacent the desired remodeling site to inhibitthe distal end 54 a of the access catheter 54 from moving once it ispositioned.

With reference to FIG. 11 a, once the access catheter 54 is guided to adesired position within the left ventricle LV, the tissue penetratingcatheter 56 may be moved from its stowed position within the accesscatheter 54 towards its protruding position such that thetissue-penetrating catheter 56 creates a passage within the wall of theleft ventricle LV. Preferably, the tissue-penetrating catheter 56creates a passage that has a shape generally corresponding to therelaxed shape of the distal end 56 a of the tissue-penetrating catheter56. If desired, one or both of the access catheter 54 and thetissue-penetrating catheter 56 may be rotated to assist thetissue-penetrating catheter 56 in creating a passage within the wall ofthe left ventricle, as illustrated by the arrows 94 in FIG. 11 b.

With reference to FIG. 11 c, once the passage has been created withinthe wall of the left ventricle LV, the push rod 76 may be used to holdthe clip 74 in position while permitting the tissue-penetrating catheter56 to be withdrawn from the passage and into the access catheter 54,thus leaving the clip 74 in place within the passage in the wall of theleft ventricle LV. Alternatively, the tissue-penetrating catheter 56 maybe withdrawn from the passage, along with the clip 74, and the push rod76 used to subsequently deploy the clip 74 into the preformed passage.The preferred method of deploying the clip 74 may depend on individualuser preference, the shape of the clip 74 or the properties of the softtissue T, among other considerations.

As illustrated in FIG. 11 c, with the distal end of the access catheter54 and balloon 64 pressed against the wall of the left ventricle LV, theclip 74 is inhibited from moving substantially toward its relaxedposition. With reference to FIG. 11 d, once the access catheter 54 ispulled away from the wall of the left ventricle LV, the tissueremodeling clip 74 may move substantially toward its relaxed position,thus bringing the ends 74 a, 74 b of the clip 74 toward one another todraw the portions of the ventricle wall associated with each end 74 a,74 b toward one another. Accordingly, the implantation of the clip 74thereby remodels and preferably reduces the volume of the left ventricleLV. In the illustrated arrangement, the clip 74 is implanted in the freewall of the left ventricle LV. That is, the clip 74 is implanted intotissue defining a wall of the ventricle other than the septal wall.However, in some applications it may be desirable to remodel the septalwall, such as when performing a septal defect repair. Thus, the presentsystems disclosed herein may be used to remodel the septal wall, or maybe appropriately modified to remodel the septal wall, if so desired.

In FIGS. 11 a-11 d, the implantable clip 74 is illustrated. However,other embodiments of the clip, such as the clips 80 and 90, may beimplanted in a similar manner. With reference to FIG. 11 e, the clip 80is illustrated as implanted in the wall of the left ventricle LV. In theclip 80, preferably the ends 80 a and 80 b protrude from an innersurface of the wall of the left ventricle and the pledgets 82 contactthe inner surface of the wall of the ventricle LV to inhibit the ends 80a, 80 b from withdrawing into the wall of the left ventricle.

FIG. 12 illustrates a plurality of remodeling clips 80 implanted withinthe wall of the left ventricle to remodel the left ventricle LV and,preferably, reduce the volume of the left ventricle LV. In someapplications, only one clip 74, 80, 90 may be desired and, in otherapplications, a plurality of clips 74, 80, 90 may be used depending onwhat level of remodeling, or reduction in volume, is desired. In apreferred method, enough clips 74, 80, 90 are implanted to substantiallycompletely fold away the akinetic portion of the ventricle tissue.However, it is contemplated that one of skill in the art will be able todetermine a suitable number of clips 74, 80, 90 to be implanteddepending on a particular application, the level of remodeling desired,the properties of the clip 74, 80, 90, and the properties of the softtissue, among other considerations.

FIGS. 13-17 illustrate a second embodiment of a tissue remodelingsystem, generally referred to by the reference numeral 100. Preferably,the system 100 is a catheter-based tissue remodeling system that isconfigured to facilitate the remodeling of soft tissue of a patient at adesired site that is accessed through the patient's vasculature. Theillustrated system 100 is configured to remodel a patient's heart and,preferably, reduce the volume of the left ventricle of the heart.However, as described above, the systems and methods disclosed hereinmay be used to otherwise manipulate, gather, fold, tie or join softtissue, such as to achieve a closing of a tissue cavity, for example.

The system 100 includes a catheter assembly 102 including a plurality ofcoaxial catheter bodies. In the illustrated arrangement, the catheterassembly 102 includes a guide catheter, or access catheter 104. Adelivery catheter 106 is movable within a lumen of the access catheter104. Preferably, a guide wire 108 is movable within a lumen of thedelivery catheter 106. The catheter 102 is configured to deliver animplant, or collapsible tissue anchor 110, to a desired tissueremodeling site, such as the left ventricle of the heart in theillustrated arrangement, for example.

Preferably, the access catheter 104 is substantially similar to theaccess catheter 54 of the system 50 of FIGS. 1-8. The access catheter104 includes a distal end 104 a configured to be introduced into theleft ventricle of a patient's heart and a proximal end 104 b defining ahandle. The access catheter 104 may be of any suitable size, shape, andlength to extend from the desired remodeling site to a site external thepatient through a suitable route. For example, the illustrated catheter102 preferably is sized to extend from a left ventricle of a patient'sheart to an external site adjacent the patient's femoral artery.Preferably, the access catheter 104 may have an outer diameter of about26 F and an inner (lumen) diameter of about 23 F. However, othersuitable dimensions may be used to suit a desired application.Furthermore, the catheter 102 may be constructed of any suitablematerial for use in a medical catheter application, as described above.

The delivery catheter 106 is configured to be axially movable within theaccess catheter 104. The delivery catheter 106 includes a distal end 106a, which is configured to support the tissue anchor 110, and a proximalend 106 b defining a handle. The delivery catheter 106 may beconstructed from any suitable material, as described above, andpreferably has an outer diameter of about 0.25 inches and an inner(lumen) diameter of about 0.125 inches. However, the dimensions may beadjusted to suit a desired application.

The guide wire 108 preferably is configured to be deliverable throughthe vasculature of a patient to the left ventricle as an individualcomponent to permit the access catheter 104 and delivery catheter 106 tobe introduced into the left ventricle by being passed over thepreviously placed guide wire 108. Preferably, the guide wire 108includes a tip 111 at its distal end 108 a that is configured to beatraumatic to tissue that it comes into contact with. Desirably, theguide wire 108 also includes a proximal end 108 b, which defines ahandle or other structure that permits a user to manipulate the guidewire 108.

With reference to FIGS. 14 and 15, desirably, the delivery catheter 106includes a docking tip 112 at its distal end 106 a. Preferably, the tip112 defines an outer surface that has a reduced diameter relative to adiameter of the outer surface of the remainder of the delivery catheter106. The docking tip 112 is sized and shaped to support a proximal endof the tissue anchor 110 thereon. Thus, preferably, an outer diameter ofthe tissue anchor 110 is generally equal to an outer diameter of thedelivery catheter 106 such that when the tissue anchor 110 is positionedon the tip 112, the transition between the catheter 106 and the tissueanchor 110 is relatively seamless. Although the collapsible tissueanchor 110 is illustrated as surrounding the docking tip 112 in theillustrated arrangement, other suitable arrangements to interconnect thetissue anchor 110 and the delivery catheter 106 may also be employed.

Preferably, the delivery catheter 106 includes a retention mechanism 114that is configured to secure the tissue anchor 110 to the distal end 106a of the delivery catheter 106 and selectively release the tissue anchor110 from the delivery catheter 106. In the illustrated arrangement, aretention wire 116 is slidably received within a passage 118 defined bya wall of the delivery catheter 106. A distal end 116 a of the retentionwire 116 is configured to extend radially outwardly relative to thecatheter 106, from the passage 118, into an aperture 120 of the tissueanchor 110. A proximal end 116 b of the retention wire 116 includes ahandle, or other suitable structure, which permits a user to retract theretention wire 116 within the passage 118 to release the tissue anchor110 from the delivery catheter 106.

Alternatively, other suitable arrangements to retain and selectivelyrelease the tissue anchor 110 may also be employed. In somearrangements, for example, the tissue anchor 110 and catheter 106 maycooperate through a snap-fit arrangement in which an interferencesurface of the catheter 106 contacts an interference surface of thetissue anchor 110 to inhibit the anchor 110 from unintentionallybecoming separated from the catheter 106. In such an arrangement, oncethe tissue anchor 110 is implanted within soft tissue, the anchor 110may be automatically separated from the catheter 106 when a pullingforce is applied to the catheter 106, as the tissue anchor 110preferably will remain in place within the tissue.

FIGS. 16 a and 16 b illustrate the tissue anchor 110 removed from thedelivery catheter 106. Preferably, the tissue anchor 110 includes a baseportion 130 and a plurality of legs 132 which extend from the baseportion 130. Desirably, the tissue anchor 110 includes between about 2and 8 legs 132 and, preferably, between about 3 to 5 legs 132. Theillustrated tissue anchor 110 includes three legs 132. However, othersuitable numbers of legs 132 may be provided in accordance with therequirements an individual application.

Preferably, the tissue anchor 110 is a hollow member having a relativelythin wall thickness dimension. Preferably, the tissue anchor 110 isconstructed of a metal material and, more preferably, from a shapememory material, such as NiTi, for example. Desirably, the base 130 isgenerally cylindrical in shape and the legs 132, preferably, are unitarywith the base 130 and extend from the wall thereof. The base 130 mayhave an outer diameter of about 0.25 inches and an inside diameter ofabout 0.188 inches, for an anchor 110 configured to be implanted into aleft ventricle of a patient's heart. However, the dimensions may bealtered to achieve desired properties of the anchor 110 to suit anindividual application, such as the closure of a cavity or hole, forexample. The legs 132 may be created by cutting away material from aninitial work piece, or sleeve, using a laser cutting method, or othersuitable fabrication method.

Preferably, the legs 132 are movable, or flexible, relative to the base130 between a relaxed position, wherein the legs 132 extend radiallyoutward from the base 130, to a collapsed position, or tissue-remodelingposition, wherein the legs 132 are biased inwardly from their relaxedposition. Preferably, in the collapsed position, the legs 132 aregenerally aligned with the wall of the base 130. However, in someapplications, the legs 132 may extend radially outward from the base130, or radially inward from the base 130, in the tissue-remodelingposition.

With reference to FIG. 17 c, preferably, a retention member 134 isconfigured to retain the legs 132 in the tissue remodeling position. Inthe illustrated arrangement, the retention member 134 is in the form ofa sleeve which slides over an outer surface of the legs 132, as isdescribed in greater detail below. However, other suitable retentionmechanisms may also be employed.

Each of the legs 132 preferably includes a pointed tissue piercing end136 to permit the legs 132 to penetrate soft tissue of a patient, suchas the wall of the left ventricle of the patient's heart. In addition,preferably the legs 132 include one or more barbs 138, which areconfigured to permit the legs 132 to enter soft tissue, in a firstdirection, and inhibit the legs 132 from being removed from the softtissue in the opposite direction. Thus, once the legs 132 havepenetrated the soft tissue, preferably, the tissue anchor 110 remainsembedded in the tissue.

Desirably, the tissue anchor 110 is configured to inhibit the retentionmember 134 from inadvertently becoming dislodged from the tissue anchor110. In the illustrated arrangement, the base 130 includes a pluralityof pawls, or tabs 140, which are configured to permit the retentionmember 134 to move toward the distal end of the tissue anchor 110 andinhibit the retention member 134 from moving away from the distal end,toward the proximal end of the tissue anchor 110 past the tabs 140.Desirably, the tabs 140 are generally semi-circular in shape andcomprise an outwardly-bent portion of the material of the base 130portion of the tissue anchor 110. Thus, the tabs 140 bend inwardly, intogeneral alignment with the base 130, to permit the retention sleeve 134to pass over. Once the retention sleeve 134 has passed over the tab 140,it returns to its outwardly-bent position to interfere with an attemptof the retention sleeve 134 in moving back over the tab 140, asillustrated in FIG. 17 c. In some arrangements, tabs may also be definedby the legs 132. Furthermore, in an alternative arrangement, the tabs140 may be defined by members that are separate from, and attached to,the tissue anchor 110.

In the illustrated arrangement, the base 130 includes several rows oftabs 140 wherein each row includes multiple tabs 140 arranged around thecircumference of the base 130. In the illustrated arrangement, thetissue anchor 110 includes three rows of tabs 140, wherein each rowincludes three tabs 140 equally spaced about a circumference of the base130. However, other suitable arrangements to permit unidirectionalmovement of the retention member 134 may also be used.

FIGS. 17 a through 17 c illustrate the tissue anchor 110 in severalstates of deployment from the catheter assembly 102. With reference toFIG. 17 a, desirably the delivery catheter 106 is positioned within theaccess catheter 104 such that the tissue anchor 110 is substantiallyentirely enclosed within the access catheter 104 and constrained therebyinto a collapsed position.

With reference to FIG. 17 b, when the tissue anchor 110 is deployed fromthe access catheter 104, the legs 132 are permitted to move toward theirrelaxed position. It should be noted that the radial expansion of thelegs 132 toward their relaxed position may be influenced by the distanceof which the tissue anchor 110 is exposed from the access catheter 104.In some applications, legs 132 of the tissue anchor 110 may becompletely deployed from the access catheter 104 prior to the legs 132contacting soft tissue. Thus, in the absence of any other restrainingforce, the legs 132 would be in their fully relaxed position whencontact with the soft tissue is made. In other applications, however,the legs 132 may be retained partially within the access catheter 104 sothat the legs 132 are constrained from moving to their fully relaxedposition. Accordingly, the diameter of a circle defined by the legs 132(or the distance between the legs 132 and an axis of the catheter 104)may be altered as desired prior to contact with the soft tissue. Inaddition, other methods of facilitating the tissue anchor 110 ingrabbing a portion of soft tissue of a desired size or shape may also beused.

With reference to FIG. 17 c, the retention member, or locking sleeve134, may be slid over the delivery catheter 106 and on to the tissueanchor 110 by a pusher catheter 142. The retention sleeve 134 may bepushed a sufficient distance on to the tissue anchor 110 to move thelegs 132 toward a tissue remodeling position to achieve a desired amountof remodeling. Desirably, the tabs 140 inhibit the retention sleeve 134from becoming disengaged with the tissue anchor 110. Alternatively, thelegs 132 may be moved toward a tissue-remodeling position by anothermember and the retention sleeve 134 may be used simply to retain thelegs 132 in the desired tissue-remodeling position.

FIGS. 18-22 illustrate a preferred method of remodeling soft tissue of apatient using the system 100 of FIGS. 13-17. The illustrated methodutilizes the system 100 to remodel the left ventricle of a patient'sheart and, preferably, to reduce the volume of the left ventricle.Desirably, access to the left ventricle is gained through the patient'svasculature beginning at an insertion site in the femoral artery F, asshown in FIG. 9. However, other methods of gaining access to the leftventricle may also be used.

With reference to FIG. 18, the guide wire 108 may be advanced throughthe patient's vasculature, from the femoral artery F, to enter the leftventricle LV through the aorta A using a suitable imaging technique, asdescribed above. The guide wire 108 is positioned preferably such thatits distal end 108 a contacts a portion of the wall of the leftventricle LV where remodeling is desired. Subsequently, the deliverycatheter 106 and access catheter 104 may be advanced over the guide wire108, either individually or together, until the distal end of eachapproaches the wall of the left ventricle LV. Preferably, the distal endof the access catheter 104 and delivery catheter 106 are spaced from thewall of the left ventricle LV as illustrated in FIG. 18.

With reference to FIG. 19, the delivery catheter 106 may be advancedrelative to the access catheter 104 and guide wire 108 such that thetissue anchor 110 is deployed therefrom. Once the tissue anchor 110 isat least partially deployed from the access catheter 104, the legs 132may move toward their relaxed, or radially outward position. Asdescribed above, the distance that the tissue anchor 110 is deployedfrom the access catheter 104, which preferably applies a restrainingforce to the legs 132, influences a distance that the legs 132 mayexpand from a center axis of the catheter 104. Such a technique may beused to determine the amount of tissue grasped by the legs 132 of thetissue anchor 110. In the illustrated arrangement, the tissue anchor 110is shown completely deployed from the access catheter 104.

With reference to FIG. 20, the delivery catheter 106 and, if desired,the access catheter 104, may be moved relative to the guide wire 108toward the wall of the left ventricle LV until the tips 136 of the legs132 of the tissue anchor 110 penetrate the wall of the left ventricleLV. Desirably, with the illustrated tissue anchor 110, the legs 132 donot penetrate an outer surface of the heart H. However, in somearrangements, it may be desirable that the legs 132 pass completelythrough the wall of the heart H. Once the legs 132 have been entered thewall of the left ventricle LV, the barbs 138 preferably inhibit the legs132 from being removed therefrom.

With reference to FIG. 21, the access catheter 104 may be removed fromthe delivery catheter 106 to permit the locking clip 134 to bepositioned over the delivery catheter 106. The pusher catheter 142 maythen be used to move the locking ring 134 to the distal end of thedelivery catheter and over the tissue anchor 110 to move the legs 132toward their tissue-remodeling position. As described above, the lockingsleeve 134 may be moved on to the tissue anchor 110 a sufficientdistance to move the legs 132 until a desired level of remodeling isaccomplished. The pusher catheter 142 may then be removed and the tabs140 of the tissue anchor 110 inhibit the locking ring 134 from becomingdisengaged with the tissue anchor 110 and thereby retain the tissueanchor 110 in its tissue remodeling position. Alternatively, the accesscatheter 104 may be adapted to carry and deploy the locking sleeve 134to eliminate the need for a separate pusher catheter 142.

With reference to FIG. 22, the tissue anchor 110 is shown in its tissueremodeling orientation configured to reduce the volume of the leftventricle LV of the patient's heart H. Once the retaining sleeve 134 ispositioned as desired on the tissue anchor 110, the pusher catheter 142and guide wire 108 may be removed, leaving the tissue anchor 110implanted in place in the left ventricle LV. If desired, more than onetissue anchor 110 may be deployed using a similar method to create aplurality of tissue folds, depending on the level of remodeling orvolume-reduction desired. The multiple tissue anchors 110 may bearranged relative to one another in any suitable orientation to achievea desired degree or shape of tissue remodeling. For example, the tissueanchors 110 may be arranged along a line generally passing through thetissue area that is desired to be remodeled.

FIGS. 23-31 illustrate another embodiment of a tissue remodeling systemgenerally referred to by the reference numeral 150. The tissueremodeling system 150 is configured to deliver a suture to soft tissueof a patient to facilitate remodeling of the soft tissue of a patient.Preferably, a plurality of sutures are delivered to accomplish thetissue remodeling. The illustrated system 150 is configured to remodelof the left ventricle of a patient's heart and, preferably, to reducethe volume of the left ventricle using a percutaneous approach throughthe patient's vasculature. Preferably, the vasculature is accessedthrough an insertion site in the patient's femoral artery. In addition,other remodeling, tissue joining or tying can be accomplished with theillustrated system 150 or modifications thereof.

The illustrated system 150 includes a catheter assembly 152 including aguide catheter, or access catheter 154, and a suture delivery catheter156, which is axially slidable within the access catheter 154. Thecatheter assembly 152 is configured to be insertable into a patient'svasculature and, preferably, directed to the patient's left ventricle tofacilitate a remodeling of the ventricle.

The access catheter 154 preferably includes a distal end 154 aconfigured to be insertable into the patient's left ventricle. Theproximal end 154 b of the access catheter 154 is configured to remainoutside of the patient and, preferably, defines a handle. The accesscatheter 154 may be constructed from any suitable material, as describedabove, and may be of any suitable size and shape. In the illustratedembodiment, the access catheter 154 has an outer diameter of up to about26 F and an inner (lumen) diameter of about 23 F. In addition, ifdesired, the access catheter 154 may be steerable, as described inconnection with the catheter 54 of FIGS. 1-3.

The suture delivery catheter 156 includes a distal end portion 156 athat is configured to deliver an end of a suture through the soft tissueof a patient and, preferably, permit the end of the suture to be removedfrom the patient along with the catheter 156. A proximal end 156 b ofthe suture delivery catheter 156 is configured to be exposed from theaccess catheter 154 and, preferably, defines a handle. The suturedelivery catheter 156 may be constructed from any suitable material, asdescribed above, and may be of any suitable size or shape. In theillustrated arrangement, the catheter 156 may have an outer diameter ofabout 22 F. However, the catheter 156 may be constructed with othersuitable dimensions as well.

The distal end 156 a of the suture delivery catheter 156 preferablydefines a cavity, or recess 158, which is configured to receive aportion of the wall of the patient's left ventricle. In one arrangement,the recess 158 may be generally semi-cylindrical in shape. Once the softtissue is positioned within the recess 158, the suture delivery catheter156 is configured to permit an end of the suture to be passed throughthe tissue. Preferably, the recess 158 is sized such that the suturepasses through an inner surface of the wall of tissue, without passingthrough the outer surface of the wall. To assist in positioning tissuewithin the recess 158, preferably, a vacuum passage 160 communicateswith the recess 158 at one end and extends through a wall of the suturedelivery catheter 156 to the proximal end 156 b. A vacuum source 162preferably is connected to the vacuum passage 160 by a suitableconnection.

Preferably, the catheter 152 also includes a stabilizer mechanism 164that is configured to assist in stabilizing the catheter 152 within theleft ventricle while the suture is being passed through the wall of theleft ventricle. The stabilizer mechanism 164 may also be useful toassist in positioning the distal end 152 a of the catheter 152. Theillustrated stabilizer mechanism 164 includes a stabilizer wire 166, aportion of which is exposed in the form of a loop near a distal end 156a of the suture delivery catheter 156. A distal end 166 a of thestabilizer wire 166 preferably is embedded in a distal end 156 a of thesuture delivery catheter 156. From the distal end, 166 a, the stabilizerwire 166 extends in a loop external to the suture delivery catheter 156until it passes into an opening 168 in the suture delivery catheter 156and extends to a proximal end of the suture delivery catheter 156through a passage 170.

A proximal end of the stabilizer wire 166 defines a handle. Thus, a usermay push the handle of the proximal end 166 b of the stabilizer wire 166to enlarge the size of the loop of the stabilizer wire 166 at the distalend 156 a of the suture delivery catheter 156. Conversely, if the handleof the proximal end 166 b of the stabilizer wire 166 is pulled away fromthe proximal end 156 b of the suture delivery catheter 156, the size ofthe loop is reduced. The stabilizer wire 166 may be manipulated to varysize of the exposed loop to press against an inner surface of the leftventricle to maintain the distal end 156 a of the suture deliverycatheter 156 in contact with a wall of the left ventricle. Furthermore,preferably, the stabilizer wire 166 may be retracted completely, ornearly completely, within the suture delivery catheter 156 so as not tointerfere with movement of the catheter 156 within the access catheter154.

Preferably, the system 150 also includes a suture delivery device 172.The suture delivery device 172 preferably includes a passage 174 definedby the body of the suture delivery catheter 156. Preferably, a distalend 174 a of the suture passage 174 communicates with the recess 158 anda proximal end 174 b of the suture passage 174 opens from a proximal endof the suture delivery catheter 156.

A push rod 176 extends through the suture passage 174. A distal end 176a of the push rod 176 carries a releasable tissue penetration member, orneedle 178, which is configured to carry one end of a suture 180. Aproximal end 176 b of the push rod 176 defines a handle that is externalof the suture delivery catheter 156. Thus, the suture passage 174preferably is sized and shaped to accommodate both a suture 180 and thepush rod 176. In the illustrated arrangement, the suture passage 174 mayhave a diameter of about 0.065 inches to accommodate a push rod 176having a diameter of about 0.045 inches (17 Gauge). However, the passage174 and push rod 176 may have other suitable dimensions to suit adesired application.

In the illustrated arrangement, the needle 178 and the push rod 176 areconnectable by a snap-fit arrangement, which is configured to retain theneedle 178 on the push rod 176, once assembled, and permit the needle178 to be selectively removed from the push rod 176 upon application ofa sufficient removal force. Furthermore, an end of the suture 180 may becoupled to the needle 178 in any suitable manner. In the illustratedembodiment, the suture passes through an aperture 181 in the push rod176 (FIG. 24) before being secured to the needle 178.

The suture delivery catheter 156 preferably also defines a needle trap182 on an end of the recess 158 opposite the suture passage 174.Desirably, the needle trap 182 is aligned with the suture passage 174such that the needle 178 will enter the trap 182 once it has passedthrough the recess 158. In the illustrated arrangement, the need trap182 is an elongate passage configured to receive the needle 178 andinhibit the needle 178 from being released from the trap 182. The needletrap 182 may be of any suitable construction to permit the needle 178 toenter the trap 182 in a first direction and inhibit the needle 178 frombeing removed. In one arrangement, the trap 182 may comprise one or moreoriented ribs, barbs or surface features that exhibit slight resistanceto entry of the needle 178, but exhibit significantly greater resistanceto the removal of the needle 178. In addition, other suitablearrangements may also be used.

Thus, once positioned within the trap 182, the needle 178 remains in thetrap 182 and is disconnected from the push rod 176 as the push rod 176is retracted from the suture delivery catheter 156. Thus, the needle 178and suture 180 may be pushed through the tissue occupying the recess158, entering the tissue at a first location and exiting the tissue at asection location, until the needle 178 is received within the trap 182.The push rod 176 may then be retracted from the suture delivery catheter156 leaving the needle 178 within the trap 182 and the suture 180extending through the tissue. The suture 180 may be pulled through thetissue along with the suture delivery catheter 156 as the suturedelivery catheter 156 is removed from the left ventricle, as isdescribed in greater detail below. As a result, both ends of the suture180 will be external the patient, with the suture passing through asection of tissue. Applying tension to both ends of the suture 180 willtend to draw the tissue portions associated with the entry and exitlocations of the suture 180 towards one another.

With reference to FIGS. 26-28, the tissue remodeling system 150 alsoincludes a catheter 190 configured to deliver a retaining clip 192,which is configured to retain at least one suture 180, and preferably aplurality of sutures 180, in a gathered position, as is described ingreater detail below. The retaining clip delivery catheter 190preferably includes an outer catheter body 194 and an inner catheterbody 196. The outer catheter 194 and inner catheter 196 are coaxial withone another and configured to cooperate to deliver the retaining clip192 through the access catheter 154. In the illustrated arrangement, theouter catheter 194 may have an outer diameter of about 22 F, with alumen of about 17 F. The inner catheter 196 may have an outer diameterof about 12 to 14 F, with a lumen of about 10 F. Other suitabledimensions may be used to suit an individual application.

With reference to FIG. 27, preferably, the retaining clip 192 issupported on a distal end portion 196 a of the inner catheter 196. Adistal end portion 194 a of the outer catheter 194 is positionedadjacent the retaining clip 192. The outer catheter 194 is movablerelative to the inner catheter 196 to selectively push the retainingclip 194 off of the distal end 196 a of the inner catheter 196.

With reference to FIGS. 28 a and 28 b, desirably the retaining clip 192is formed from a shape memory material, such as NiTi, for example, suchthat the clip 192 is moveable from a biased opened position, such aswhen supported on the inner catheter 196, to a relaxed position, whereinthe retaining clip 192 coils over on itself, as illustrated in FIG. 28b. When in its relaxed position, the retaining clip 192 is configured toretain one or more sutures 180 in a gathered orientation, as isdescribed in greater detail below.

With reference to FIG. 29, preferably, both the suture delivery catheter156 and the retaining clip delivery catheter 190 may be removed from theaccess catheter 154. A knot pusher 200 may be used to push a knot 202from external a proximal end 154 b of the access catheter 154 toexternal a distal end 154 a of the access catheter 154 and, preferably,against the retaining clip 192. Thus, one or more knots 202 may be usedto inhibit, or prevent, the retaining clip 192 from moving relative tothe sutures 180 to advantageously retain the sutures 180 in a gatheredorientation. The knot pusher 200 preferably is of a conventionalconstruction comprising an elongate body of stainless steel havingdistal tip formed into a loop, as will be appreciated by one of skill inthe art. Other suitable methods or devices to move a knot 202 along thesutures 180 or otherwise inhibit undesired movement of the retainingclip 192 may also be used.

The tissue remodeling system 150 preferably also includes a suturecutting device 210. The suture cutter assembly 210 preferably includes acatheter 212 having a distal end 212 a and a proximal end 212 b.Desirably, the proximal end 212 b defines a handle. The catheter 212preferably includes a distal end section 214 and a proximal end section216. Preferably, the proximal end 216 includes a semi-cylindricalpassage 218 and a suture passage 220. A push rod 222 extends through thepassage 218 and, preferably, is also semi-cylindrical in shape togenerally match the shape of the passage 218. A distal end 222 a of thepush rod 222 preferably includes a cutting surface 223 and a proximalend 222 b of the push rod defines a handle.

The distal end section 214 preferably also includes a semi-cylindricalpassage 226 that is closed by a plug 228. Further, the distal endsection 214 preferably includes a suture passage 230. In the illustratedarrangement, the distal end section 214 defines a working space 232between the passage 226 and suture passage 230 of the distal end section214 and the passage 218 and suture passage 220 of the proximal endsection 216. Desirably, the distal end section 214 is oriented such thatthe suture passage 220 and the suture passage 230 are directly oppositeone another. The suture 180 may be passed through the passages 220 and230 so that the suture 180 will pass through the working space 232 pastthe cutting surface 223 of the push rod 222. The push rod 222 may beadvanced to cut the suture between the cutting surface 223 of the distalend 222 a and the plug 228. Alternatively, the distal end section 214may be rotatable relative to the proximal section 216 such that thesuture passages 220 and 230 may be selectively aligned, the suturepassed through the passages 220 and 230, and the distal end section 214rotated relative to the proximal section 216 such that the suturepassages 220 and 230 are opposite one another so that the suture may becut. In addition, other suitable devices or methods may also be used tocut the one or more sutures 180, if desired.

With reference to FIGS. 32-40, a preferred method of remodeling tissuewith the system 150 of FIGS. 23-31 is illustrated. As described above,the preferred method is utilized to reduce a volume of the leftventricle LV of the heart H of a patient P. With reference to FIG. 32,desirably, the system 150 is configured to be introduced into thevasculature V of the patient P at a desired site. In the illustratedarrangement, the catheter 152 is introduced through the femoral artery Fof the patient P and is guided to the left ventricle LV.

With additional reference to FIGS. 33 a and 33 b, the suture deliverycatheter 156 is positioned within the left ventricle LV so that thesuture may be passed through a desired site of the wall of the leftventricle LV. The suture delivery catheter 156 may be positioned bysteering one or both of the access catheter 154 and suture deliverycatheter 156. In addition, the stabilizing wire 166 may be used toassist in positioning the suture delivery catheter 156 and retaining thesuture delivery catheter 156 in a desired position within the leftventricle LV.

Once positioned as desired, the vacuum source 162 may be activated todraw tissue within the recess 158 (FIG. 24) of the suture deliverycatheter 156. The push rod 166 may then be advanced to push the needle178 through the tissue occupying the recess 158. The push rod 166preferably is advanced until the needle 178 enters the trap 182 wherebythe suture 180 is passed through the tissue within the recess 158.

With reference FIGS. 34 a and 34 b, the stabilizing wire 166 may beretracted and the vacuum source 162 deactivated. The suture deliverycatheter 156 may be withdrawn thereby pulling the suture 180 through thetissue and removing the end of the suture 180 along with the suturedelivery catheter 156. Thus, once the suture delivery catheter 156 iscompletely removed from the patient's vasculature, both ends of thesuture 180 will be external the patient with the suture 180 passingthrough a section of the tissue of the left ventricle LV, entering thetissue at a first location and exiting the tissue at a second locationspaced from the first location.

With reference to FIGS. 35 and 36, preferably additional sutures 180 arepositioned within the left ventricle in desired positions relative tothe initial suture 180. Preferably, the multiple sutures 180 arepositioned such that, when drawn together, the tissue of the leftventricle will be drawn together along a desired suturing line aroundthe diseased portion of the ventricle, which will reduce the volume ofthe ventricle. However, in some arrangements, a desired level ofremodeling, tying or tissue joining may be accomplished with only onesuture 180.

With references to FIGS. 37-39, once a desired number of sutures 180 areplaced within the left ventricle LV, the retaining clip deliverycatheter 190 is advanced over the sutures 180 and within the accesscatheter 154 until a distal end of the retaining clip delivery catheter190 is within the left ventricle LV. The retaining clip deliverycatheter 190 is advanced until the sutures 180 are drawn together toreduce the volume of the left ventricle LV, preferably much like theclosing of a pursestring suture. When the sutures 180 are drawn togetherto a sufficient degree, the outer catheter 194 may be advanced relativeto the inner catheter 196 such that the retaining clip 192 is deployedtherefrom, preferably substantially as described above with reference toFIG. 27.

FIG. 40 illustrates the gathered sutures retained by the retaining clip192 such that the volume of the left ventricle LV is reduced.Preferably, the left ventricle LV is reduced to a volume thatapproximates the normal size of the ventricle prior to the onset ofheart disease, or that results in an acceptable level of performance. Inone arrangement, the dyskinetic portion of the left ventricle LV isessentially eliminated from defining the working chamber of theventricle LV. If the dyskinetic portion of the ventricle LV is largeenough, the plurality of sutures 180, in a drawn together orientation,create two chambers within the ventricle: a working chamber WC and adormant chamber DC. Preferably, the sutures 180 draw the wall of theventricle together to an extent that the chambers WC and DC aresubstantially isolated from one another. That is, although some minoramount of fluid communication may exist between the chambers WC and DC,the dormant chamber DC does not effectively contribute to the workingvolume of the ventricle LV.

As illustrated, preferably, a plurality of knots 202 are created withinthe sutures 180 and advanced to a position behind the retainer clip 192to retain the sutures 180 in a drawn together position. Preferably, theknots 202 are advanced from external the patient P to behind theretainer clip 192 by a knot pusher, such as the knot pusher 200described in relation to FIG. 29. However, other suitable methods ordevices for creating knots, or otherwise retaining the retainer clip 192in a desired position, may also be used. In addition, the ends of thesutures 180 are cut, preferably using a device substantially asdescribed with respect to FIGS. 30 and 31. However, other suitablemethods or devices for cutting the sutures 180 may also be used.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. In particular, while the present tissue remodeling systems andmethods have been described in the context of particularly preferredembodiments, the skilled artisan will appreciate, in view of the presentdisclosure, that certain advantages, features and aspects of the systemmay be realized in a variety of other applications, many of which havebeen noted above. Additionally, it is contemplated that various aspectsand features of the invention described can be practiced separately,combined together, or substituted for one another, and that a variety ofcombination and subcombinations of the features and aspects can be madeand still fall within the scope of the invention. Thus, it is intendedthat the scope of the present invention herein disclosed should not belimited by the particular disclosed embodiments described above, butshould be determined only by a fair reading of the claims.

1. A cardiac treatment apparatus, comprising: a catheter having a catheter body configured to be introduced into a heart chamber through vasculature, said catheter comprising a clip having end portions, said clip movably mounted in said catheter body such that one end portion of said catheter body enters an interior surface of a wall of said heart and creates a channel within said wall that does not pass through an exterior surface of the wall to introduce at least a substantial portion of said clip into said channel and said wall, wherein at least an intermediate portion of said clip is embedded in said wall, no portion of said clip passes through the exterior surface of said wall, and said end portions of said clip are resiliently biased to move relative to each other such that said movement of said end portions draws tissue portions towards each other.
 2. The apparatus of claim 1, wherein a distal end of said catheter is configured to move towards a non-linear relaxed shape in the absence of a constraining force.
 3. The apparatus of claim 2, wherein said non-linear relaxed shape comprises a helical shape.
 4. The apparatus of claim 1, wherein said clip comprises a unitary member defining said first end, said second end and said intermediate portion.
 5. The apparatus of claim 4, wherein said clip additionally comprises stabilizing components at each of said first and second ends to inhibit movement of said clip relative to the ventricle wall.
 6. The apparatus of claim 1, wherein said clip is carried within a lumen of said delivery catheter.
 7. An assembly for remodeling a heart ventricle, comprising: an access catheter defining a lumen, said access catheter configured to be deliverable from an access site through vasculature to the heart ventricle; a delivery catheter configured to be movable within said lumen of said access catheter, a distal end of said delivery catheter defining a tissue-penetrating tip; a tissue-remodeling clip carried by said delivery catheter, said clip having a first end, a second end and an intermediate portion connecting said first and second ends; wherein said delivery catheter may be advanced relative to said access catheter such that said tissue-penetrating tip of said delivery catheter penetrates a wall of the heart without passing completely through the wall and said delivery catheter creates a channel within the wall that does not pass completely through the wall, said tissue-remodeling clip being deployable from said delivery catheter and into said channel wherein said clip is embedded within said wall without passing entirely through the wall and wherein said first and second ends of said clip are resiliently biased towards one another to remodel the wall of the heart ventricle.
 8. The assembly of claim 7, wherein a distal end of said delivery catheter is configured to move towards a non-linear relaxed shape when advanced from said access catheter.
 9. The assembly of claim 8, wherein said non-linear relaxed shape comprises an arcuate shape.
 10. The assembly of claim 8, wherein said non-linear relaxed shape comprises a helical shape.
 11. The assembly of claim 7, wherein said distal end of said delivery catheter is sized and shaped such that said channel passes through a portion of the ventricle wall without passing through an exterior surface of the ventricle wall.
 12. The assembly of claim 7, wherein said clip comprises a unitary member defining said first end, said second end and said intermediate portion.
 13. The assembly of claim 12, wherein said unitary member is constructed from a shape memory alloy.
 14. The assembly of claim 12, wherein said clip additionally comprises stabilizing components at each of said first and second ends to inhibit movement of said clip relative to the ventricle wall.
 15. The assembly of claim 14, wherein said stabilizing components comprise pledgets.
 16. The assembly of claim 14, wherein said stabilizing components comprise barbs.
 17. The assembly of claim 7, wherein said intermediate portion of said clip has a generally circular cross-sectional shape.
 18. The assembly of claim 7, wherein a distal end of said access catheter carries an inflatable, annular balloon.
 19. The assembly of claim 18, wherein said balloon is configured to contact an interior surface of the ventricle wall and space a distal end surface of said access catheter from the interior surface.
 20. The assembly of claim 7, additionally comprising a push rod configured to be movable within said lumen of said delivery catheter, a distal end of said push rod configured to contact clip such that said push rod may be advanced relative to said delivery catheter to deploy said clip. 